Featured Research

from universities, journals, and other organizations

Neuroscientists identify class of cortical inhibitory neurons specializing in disinhibition

Date:
October 6, 2013
Source:
Cold Spring Harbor Laboratory
Summary:
New research reveals that one class of inhibitory neurons -- called VIP interneurons -- specializes in inhibiting other inhibitory neurons in multiple regions of cortex, and does so under specific behavioral conditions. The new research finds that VIP interneurons, when activated, release principal cells from inhibition, thus boosting their responses. This provides an additional layer of control over cortical processing, much like a dimmer switch can fine-tune light levels.

The cerebral cortex contains two major types of neurons: principal neurons that are excitatory and interneurons that are inhibitory, all interconnected within the same network. New research now reveals that one class of inhibitory neurons -- called VIP interneurons -- specializes in inhibiting other inhibitory neurons in multiple regions of cortex, and does so under specific behavioral conditions.

The new research finds that VIP interneurons, when activated, release principal cells from inhibition, thus boosting their responses. This provides an additional layer of control over cortical processing, much like a dimmer switch can fine-tune light levels.

The discovery was made by a team of neuroscientists at Cold Spring Harbor Laboratory (CSHL) led by Associate Professor Adam Kepecs, Ph.D. Their research, published online today in Nature, shows that neurons expressing vasoactive intestinal polypeptide, or VIP, provide disinhibition in the auditory cortex and the medial prefrontal cortex.

The researchers used molecular tagging techniques developed by team member Z. Josh Huang, a CSHL Professor, to single out VIP-expressing neurons in the vast diversity of cortical neurons. This enabled Kepecs' group, led by postdocs Hyun Jae Pi and Balazs Hangya, to employ advanced optogenetic techniques using color-coded laser light to specifically activate VIP neurons. The activity of the cells was monitored via electrophysiological recordings in behaving animals to study their function, and in vitro to probe their circuit properties.

These VIP neurons are long sought "disinhibitory" cells: they inhibit other classes of inhibitory neurons; but they do not directly cause excitation to occur in brain. Dr. Kepecs and colleagues propose that the disinhibitory control mediated by VIP neurons represents a fundamental "motif" in cerebral cortex.

The difference between neural excitation and disinhibition is akin to the difference between hitting the gas pedal and taking your foot off the breaks. Cells that specialize in releasing the brakes, Dr. Kepecs explains, provide the means for balancing between excitation and inhibition. Kepecs calls this function "gain modulation," which brings to mind the fine control that a dimmer switch provides.

The team wondered when VIP neurons are activated during behavior. When, in other words, is the "cortical dimmer switch" engaged? To learn the answer the scientists recorded VIP neurons while mice were making simple decisions, discriminating between sounds of different pitches. When they made correct choices, the mice earned a drop of water; for incorrect choices, a mild puff of air. Surprisingly, the team found that in auditory cortex, a region involved in processing sounds, VIP neurons were activated by rewards and punishments. Thus these neurons appeared to mediate the impact of reinforcements and "turn up the lights" on principal cells, to use the dimmer-switch analogy.

"Linking specific neuronal types to well-defined behaviors has proved extremely difficult," says Kepecs. These results, he says, potentially link the circuit-function of VIP neurons in gain control to an important behavioral function: learning.


Story Source:

The above story is based on materials provided by Cold Spring Harbor Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hyun-Jae Pi, Balαzs Hangya, Duda Kvitsiani, Joshua I. Sanders, Z. Josh Huang, Adam Kepecs. Cortical interneurons that specialize in disinhibitory control. Nature, 2013; DOI: 10.1038/nature12676

Cite This Page:

Cold Spring Harbor Laboratory. "Neuroscientists identify class of cortical inhibitory neurons specializing in disinhibition." ScienceDaily. ScienceDaily, 6 October 2013. <www.sciencedaily.com/releases/2013/10/131006142443.htm>.
Cold Spring Harbor Laboratory. (2013, October 6). Neuroscientists identify class of cortical inhibitory neurons specializing in disinhibition. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2013/10/131006142443.htm
Cold Spring Harbor Laboratory. "Neuroscientists identify class of cortical inhibitory neurons specializing in disinhibition." ScienceDaily. www.sciencedaily.com/releases/2013/10/131006142443.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) — President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Obama Orders Military Response to Ebola

Obama Orders Military Response to Ebola

AP (Sep. 16, 2014) — Calling the Ebola outbreak in West Africa a potential threat to global security, President Barack Obama is ordering 3,000 U.S. military personnel to the stricken region amid worries that the outbreak is spiraling out of control. (Sept. 16) Video provided by AP
Powered by NewsLook.com
UN: 20,000 Could Be Infected With Ebola by Year End

UN: 20,000 Could Be Infected With Ebola by Year End

AFP (Sep. 16, 2014) — Nearly $1.0 billion dollars is needed to fight the Ebola outbreak raging in west Africa, the United Nations say, warning that 20,000 could be infected by year end. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Obama: Ebola Outbreak Threat to Global Security

Obama: Ebola Outbreak Threat to Global Security

AP (Sep. 16, 2014) — President Obama is ordering U.S. military personnel to West Africa to deal with the Ebola outbreak, which is he calls a potential threat to global security. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins